#ifndef PID_v1_h
#define PID_v1_h
#define LIBRARY_VERSION	1.2.1

class PID
{


public:

	//Constants used in some of the functions below
#define AUTOMATIC	1
#define MANUAL	0
#define DIRECT  0
#define REVERSE  1
#define P_ON_M 0
#define P_ON_E 1

	//commonly used functions **************************************************************************
	PID(double*, double*, double*,        // * constructor.  links the PID to the Input, Output, and 
		double, double, double, int, int);//   Setpoint.  Initial tuning parameters are also set here.
										  //   (overload for specifying proportional mode)

	PID(double*, double*, double*,        // * constructor.  links the PID to the Input, Output, and 
		double, double, double, int);     //   Setpoint.  Initial tuning parameters are also set here

	void init(double*, double*, double*, double, double, double, int, int);

	void SetMode(int Mode);               // * sets PID to either Manual (0) or Auto (non-0)

	bool Compute();                       // * performs the PID calculation.  it should be
										  //   called every time loop() cycles. ON/OFF and
										  //   calculation frequency can be set using SetMode
										  //   SetSampleTime respectively

	void SetOutputLimits(double, double); // * clamps the output to a specific range. 0-255 by default, but
										  //   it's likely the user will want to change this depending on
										  //   the application



										  //available but not commonly used functions ********************************************************
	void SetTunings(double, double,       // * While most users will set the tunings once in the 
		double);         	    //   constructor, this function gives the user the option
								//   of changing tunings during runtime for Adaptive control
	void SetTunings(double, double,       // * overload for specifying proportional mode
		double, int);

	void SetControllerDirection(int);	  // * Sets the Direction, or "Action" of the controller. DIRECT
										  //   means the output will increase when error is positive. REVERSE
										  //   means the opposite.  it's very unlikely that this will be needed
										  //   once it is set in the constructor.
	void SetSampleTime(int);              // * sets the frequency, in Milliseconds, with which 
										  //   the PID calculation is performed.  default is 100



										  //Display functions ****************************************************************
	double GetKp();						  // These functions query the pid for interal values.
	double GetKi();						  //  they were created mainly for the pid front-end,
	double GetKd();						  // where it's important to know what is actually 
	int GetMode();						  //  inside the PID.
	int GetDirection();					  //

private:
	void Initialize();

	double dispKp;				// * we'll hold on to the tuning parameters in user-entered 
	double dispKi;				//   format for display purposes
	double dispKd;				//

	double kp;                  // * (P)roportional Tuning Parameter
	double ki;                  // * (I)ntegral Tuning Parameter
	double kd;                  // * (D)erivative Tuning Parameter

	int controllerDirection;
	int pOn;

	double *myInput;              // * Pointers to the Input, Output, and Setpoint variables
	double *myOutput;             //   This creates a hard link between the variables and the 
	double *mySetpoint;           //   PID, freeing the user from having to constantly tell us
								  //   what these values are.  with pointers we'll just know.

	unsigned long lastTime;
	double outputSum, lastInput;

	unsigned long SampleTime;
	double outMin, outMax;
	bool inAuto, pOnE;
};
#endif
